DEV: stop leaking data into tables during test (#21403)

This amends it so our cached counting reliant specs run in synchronize mode

When running async there are situations where data is left over in the table
after a transactional test. This means that repeat runs of the test suite
fail.

app/models/concerns/cached_counting.rb

@@ -83,9 +83,11 @@ module CachedCounting
   end
 
   def self.flush
-    @flush = true
-    @thread.wakeup
-    sleep 0.001 while @flush
+    if @thread
+      @flush = true
+      @thread.wakeup
+      sleep 0.001 while @flush
+    end
   end
 
   COUNTER_REDIS_HASH = "CounterCacheHash"
@@ -163,9 +165,30 @@ module CachedCounting
   end
 
   class_methods do
-    def perform_increment!(key)
-      CachedCounting.ensure_thread!
-      CachedCounting.queue(key, self)
+    if Rails.env.test?
+      # perform increment is a risky call in test,
+      # it shifts stuff to background threads and leaks
+      # data in the DB
+      # Require caller is deliberate if they want that
+      #
+      # Splitting implementation to avoid any perf impact
+      # given this is a method that is called a lot
+      def perform_increment!(key, async: false)
+        if async
+          CachedCounting.ensure_thread!
+          CachedCounting.queue(key, self)
+        else
+          CachedCounting.queue(key, self)
+          CachedCounting.clear_flush_to_db_lock!
+          CachedCounting.flush_in_memory
+          CachedCounting.flush_to_db
+        end
+      end
+    else
+      def perform_increment!(key)
+        CachedCounting.ensure_thread!
+        CachedCounting.queue(key, self)
+      end
     end
 
     def write_cache!(key, count, date)

spec/lib/concern/cached_counting_spec.rb

@@ -80,15 +80,15 @@ RSpec.describe CachedCounting do
       freeze_time
       d1 = Time.now.utc.to_date
 
-      RailsCacheCounter.perform_increment!("a,a")
-      RailsCacheCounter.perform_increment!("b")
-      20.times { RailsCacheCounter.perform_increment!("a,a") }
+      RailsCacheCounter.perform_increment!("a,a", async: true)
+      RailsCacheCounter.perform_increment!("b", async: true)
+      20.times { RailsCacheCounter.perform_increment!("a,a", async: true) }
 
       freeze_time 2.days.from_now
       d2 = Time.now.utc.to_date
 
-      RailsCacheCounter.perform_increment!("a,a")
-      RailsCacheCounter.perform_increment!("d")
+      RailsCacheCounter.perform_increment!("a,a", async: true)
+      RailsCacheCounter.perform_increment!("d", async: true)
 
       CachedCounting.flush
 

spec/lib/middleware/request_tracker_spec.rb

@@ -21,6 +21,7 @@ RSpec.describe Middleware::RequestTracker do
   end
 
   after do
+    CachedCounting.reset
     ApplicationRequest.disable
     CachedCounting.disable
   end

spec/models/report_spec.rb

@@ -1309,9 +1309,11 @@ RSpec.describe Report do
       end
 
       after do
+        CachedCounting.reset
         ApplicationRequest.disable
         CachedCounting.disable
       end
+
       it "works" do
         3.times { ApplicationRequest.increment!(:page_view_crawler) }
         2.times { ApplicationRequest.increment!(:page_view_logged_in) }

spec/models/web_crawler_request_spec.rb

@@ -6,7 +6,10 @@ RSpec.describe WebCrawlerRequest do
     CachedCounting.enable
   end
 
-  after { CachedCounting.disable }
+  after do
+    CachedCounting.reset
+    CachedCounting.disable
+  end
 
   it "can log crawler requests" do
     freeze_time